Fuel metering system

ABSTRACT

A fluid amplifier is used as an internal combustion engine fuel metering element, receiving fuel for both main and control fluid streams from a pump having an output flow proportional to engine speed so that the metered fuel output from the amplifier increases upon an increase in engine speed. The control fluid stream of the amplifier is regulated by a manually adjustable valve and by a valve responsive to induction system vacuum so that the metered fuel output from the amplifier increases upon an increase in manifold pressure.

United States Patent [72] Inventor Fred F. Timpner I 56} References Cited 0min"! Lake Mich- UNlTED STATES PATENTS fig 33 1970 3386,709 6/l968 Drayer 26l/DlG. 69 Patented g 10. 197 3,389,894 6/l968 Binder 26l/DlG. 69 [73] Assignee General Motors Corporation Primary Examiner-Wendell E. Burns D nit, Mi h, Attorneys-J L. Carpenter and C. K. Veenstra ABSTRACT: A fluid amplifier is used as an internal com- [54] m s sgsmm bustion engine fuel metering element, receiving fuel for both main and control fluid streams from a pump having an output [52] US. Cl. 123/119, fl p oportion l to engine speed so that the metered fuel outl23/l39 AW,26l/36A, 261/09 R, 26l/DIG. 69 put from the amplifier increases upon an increase in engine [Sl Int. Cl F02n 37/14, speed The control fluid stream of the amplifier is regulated by F02n 69/00, F02n 55/00 a manually adjustable valve and by a valve responsive to in- [50] Field of Search U 261/69 R, duction system vacuum so that the metered fuel output from 36 A, DIG. 69; 123/1 19, 139 AW the amplifier increases upon an increase in manifold pressure.

PATENTED AUG] 0197:

SHEET 2 OF 2 j INVENY'UA.

fled fffimpner HY ATTORNEY FUEL METERING SYSTEM SUMMARY OF THE INVENTION The invention set forth herein provides a new arrangement for use of a fluid amplifier as a fuel metering element. This arrangement utilizes a single phase amplifier in which both the main stream and the control stream of the amplifier comprise the fuel itself. I

This fuel system has basically a speed-density metering arrangement in which the rate of flow of the main stream is responsive to the speed of the engine while the rate of flow of the control stream is responsive to manifold pressure as well as engine speed.

The metering arrangement also provides another control over the rate of flow of the control stream in order that fuel metering may be regulated according to other engine operating parameters.

The details as well as other objects and advantages of this invention are shown in the drawings and discussed in the description of a preferred embodiment.

SUMMARY OF THE DRAWINGS FIG. I schematically illustrates the fluid amplifier metering element connected to the engine driven fuel pump and the the throttled air inlet;

FIG. 2 is a plan view of the fluid amplifier metering element and its associated control valves;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2 illustrating the manifold pressure responsive valve;

FIG. 4 is a sectional view along line 4-4 of FIG. 2 illustrating the inlet fitting and the manually operated auxiliary control valve;

'FIG. 5 is a sectional view taken along line 5-5 of FIG. 2 illustrating the amplifier outlet fittings;

FIG. 6 is a view of the fluid amplifier passages, taken along line 6-6 of FIG. 5; and

FIG. 7 is a pictorial view of the upper and lower members of the amplifier illustrating their relationship.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. I, an engine driven pump I0 draws fuel through a line I2 from a fuel supply tank 14 and delivers fuel at a rate of flow proportional to engine speed through a line 16 to a fluid amplifier element I8. A metered fuel stream is delivered from amplifier 18 through an outlet line 20 to a discharge point 22 in the combustion air flow inlet 24. A surplus fuel stream is delivered from amplifier 18 through a line 26 back to fuel supply tank 14.

Air flow through air inlet 24 is controlled by a throttle 28. Air inlet 24 includes, in this instance, an intake manifold 30 in which the pressure ranges from near atmospheric to a high degree of vacuum. A valve unit 32 controls fuel flow in amplifier 18 in accordance with pressure changes in manifold 30.

Amplifier I8, illustrated in FIGS. 2 through 7, comprises upper and lower members 34 and 36, respectively, separated by a gasket 33. The metering elements of the amplifier lie generally within lower member 36 and are best shown in FIG. 6-. An inlet chamber 40 receives fuel from line 16 (FIG. I) through an inlet fitting 42 (FIGS. 2 and 4) threaded into an opening 44 (FIGS. 4 and 7) in upper member 34. A passage 46 leads from inlet chamber 40 to an inlet port 48 opening into the upstreamend 50 of the interaction region 52.

A primary control passage 54 also extends from inlet chamber 40 to a primary control port 56 opening into the side 58 of interaction region 52 adjacent inlet port 48. A supplemental control passage 59 extends from inlet chamber 40 to interaction region 48 and is oriented to discharge in opposition to the discharge from port 56 of primary control passage 54. A divider 60 has a pair of sides 62 and 64 converging to an apex 66 disposed at the downstream end 67 of interaction region 52. 'A metered fuel outlet port 68 is located on one side of divider 60 and has a passage 70 leading to an outlet chamber 72. Outlet chamber 72 has an opening 74 which receives a fitting 76 (FIG. 5) from which line 20 (FIG. I) delivers metered fuel to air inlet 24. A surplus fuel outlet 78 is disposed on the opposite side of divider 60 and has a passage 80 leading to an outlet chamber 82. Outlet chamber 82 connects through an opening 84 (FIGS. 5 and 7) in upper member 34 to a fitting 86 (FIGS. 2 and 5) from which line 26 (FIG. I) delivers surplus fuel to supply tank 14.

A valve seat 88 formed in control passage 54 cooperates with a valve plunger 90 (FIG. 3) received through an opening 92 (FIGS. 3 and 7) in upper member 34 and sealed therein by an O-ring 94. As valve plunger 90 is withdrawn from valve seat 88, the flow of fuel through control passage 54 increases. As shown in FIG. 3, valve plunger 90 is a portion of pressure responsive valve unit 32 and is secured to a diaphragm 96 biased by a spring 98 in a valve closing direction. Valve unit 32 has a fitting I00 for receiving a vacuum line I02 (FIG. I) connected to intake manifold 30.

Referring now to FIGS. 4 and 6, a valve seat I04 is also disposed in control passage 54. It cooperates with a valve member I06 threadedly received through an opening I08 in upper member 34. As valve member I06 is moved toward valve seat 104, the flow of fuel through control passage 54 is reduced.

Valve unit 32 is mounted on a bracket I10 secured by a pair of studs II2 in a pair of openings 114 in upper member 34.

The upper and lower members 34 and 36 of amplifier I8 are secured by studs II6 passing through openings I18 in upper member 34 and threadedly received in openings in lower member 36.

In operation, fuel is delivered from pump 10 at a rate of flow proportional to engine speed. From inlet chamber 40 the fuel flows through passages 46 and 54 to inlet port 48 and control port 56. A main fuel stream is discharged from inlet port 48 longitudinally through interaction region 52. Control fuel streams are discharged from control passages 54 and 59 transversely through interaction region 52 into contact with the main stream. The main stream and control streams form a combined fuel stream having a rate of flow dependent upon the speed of the engine. As the control streams combine with the main stream from inlet port 48, the main stream is deflected. The deflection is proportional to the rate of flow of the control streams, and thus the traverse position of the path ofthe combined fuel stream corresponds to the rate of flow of the control streams. The combined fuel stream strikes divider apex 66, a portion passing through metered fuel outlet 68 as a metered fuel stream and the remainder passing through surplus fuel outlet 78 for return to supply tank 14 as a surplus fuel stream.

The rate of flow of the control fuel stream discharged from control port 56 is determined in part by vacuum responsivevalve unit 32; as throttle 28 is closed and vacuum in induction manifold 30 rises, valve plunger 90 is withdrawn from valve seat 88 to increase the rate of flow of the control fuel stream and cause the combined fuel stream to move to the left as viewed in the drawing. As this occurs, the rate of flow of the metered fuel stream decreases and the rate of flow of the surlus fuel stream increases. It will be appreciated, therefore, that as throttle 28 is closed to reduce the combustion air flow, the rate of flow of the metered fuel stream delivered to air inlet 24 also decreases.

Similarly, manually operated valve 106 may be adjusted to increase or decrease the rate of flow of the control fuel stream and thus correspondingly decrease or increase the rate of flow of the metered fuel stream. Adjustment of valve member I06 may be necessary to correct for changes in temperature, altitude, or other engine operating parameters. It will be appreciated that valve member I06 may be operated automatically as desired and that valve member 106 may be considered as representative of a series of valves disposed along control passage 54.

it will also be appreciated that various changes in the design of amplifier 18 to control the metering action are within the skill of the art. In addition, it may be desirable to deliver additional'control signals to interaction region 52 for metering purposes.

lclaim:

1. A fuel metering system for an internal combustion engine having a fuel supply and fuel pump means for delivering fue from said supply at flow rates proportional to the speed of the engine, said fuel metering system comprising:

an air inlet for combustion air flow to the engine;

a throttle disposed in said air inlet for controlling air flow therethrough;

a fluid amplifier arrangement having an interaction region including upstream and downstream ends, an inlet port opening into said stream end of said interaction region, said inlet port being adapted for connection to said pump means for receiving fuel at fuel flow rates proportional to the speed of the engine and for discharging a main fuel stream longitudinally through said interaction region, a pair of outlet ports opening from said downstream end of said interaction region, a divider separating said outlet ports, one of said outlet ports receiving a metered fuel stream from said interaction region and being connected to said air inlet for delivering the metered fuel stream to said air inlet for mixture with the combustion air flow, the other of said outlet ports receiving a surplus fuel stream from said interaction region and being adapted for connection to said fuel supply for delivering the surplus fuel stream to said fuel supply, and a control port opening into said interaction region for discharging a control fuel stream transversely through said interaction region into contact with the main fuel stream discharge from said inlet port;

and means for varying the rate of flow of the control fuel stream in accordance with changes in the pressure in said air inlet downstream of said throttle;

the main and control fuel streams forming a combined fuel stream passing longitudinally through said interaction region along a path having a transverse position varying in accordance with the rate of flow of the control fuel stream, the combined fuel stream striking said divider and forming the metered and surplus fuel streams received by said outlet ports, the rates of flow of the metered and surplus fuel streams being determined by the rate of flow and the transverse position of the path of the combined fuel stream, an increase in engine speed causing an inc rease in the rate of flow of the metered fuel stream delivered to said air inlet, and an increase in the pressure in said air inlet downstream of said throttle causing an increase in the rate of flow of the metered fuel stream delivered to said air inlet.

2. A fuel metering system for an internal combustion engine comprising:

a fuel supply;

fuel pump means for delivering fuel from said supply;

an air inlet for combustion air flow to the engine;

a fluid amplifier arrangement having an interaction region including upstream and downstream ends, an inlet port opening into said upstream end of said interaction region and connected to said fuel pump means for discharging a main fuel stream longitudinally through said interaction region, a pair of outlet ports opening from said downstream and of said interaction region, a divider separating said outlet ports, one of said outlet ports receiving a metered fuel stream from said interaction region and being connected to said air inlet for delivering the metered fuel stream to said air inlet for mixture with the combustion air flow, the other of said outlet ports receiving a surplus fuel stream from said interaction region and being connected to said fuel supply for delivering the surplus fuel stream to said fuel supply, and a control port opening into said interaction region and connected to said fuel pump means for discharging a control fuel stream transversely through said interaction region into contact with the main fuel stream discharged from said inlet port;

and means for varying the rate of flow of the control fuel stream in accordance with engine operating conditions;

the main and control fuel streams forming a combined fuel stream passing longitudinally through said interaction region along a path having a transverse position varying in accordance with the rate of flow of the control fuel stream, the combined fuel stream striking said divider and forming the metered and surplus fuel stream received by said outlet ports, the rates of flow of the metered and surplus fuel streams being determined by the rate of flow and the transverse position of the path of the combined fuel stream.

3. A fuel metering system for an internal combustion engine comprising:

a fuel supply;

fuel pump means for delivering fuel from said supply;

an air inlet for combustion air flow to the engine;

a fluid amplifier arrangement having an interaction region including upstream and downstream ends, an inlet port opening into said upstream end of said interaction region and connected to said fuel pump means for discharging a main fuel stream longitudinally through said interaction region, a divider formed at said downstream end of said interaction region, a metered fuel outlet port opening from said downstream end of said interaction region adjacent one side of said divider for receiving a metered fuel stream from said interaction region, said metered fuel outlet port being connected to said air inlet for delivering the metered fuel stream to said air inlet for mixture with the combustion air flow, a surplus fuel outlet port opening from said downstream end of said interaction region adjacent the opposite side of said divider for receiving a surplus fuel stream from said interaction region, said surplus fuel outlet port being connected to said fuel supply for delivering the surplus fuel stream to said fuel supply, and a control port opening into said interaction region on the side thereof most closely adjacent said metered fuel outlet port and connected to said fuel pump means for discharging a control fuel stream transversely through said interaction region into contact with said main fuel stream;

and means for varying the rate of flow of the control fuel stream in accordance with engine operating conditions;

the main and control fuel streams forming a combined fuel stream passing longitudinally through said interaction region along a path having a transverse position varying in accordance with the rate of flow of the control fuel stream; the combined fuel stream striking said divider and forming the metered and surplus fuel streams received by said outlet ports, the rates of flow of the metered and surplus fuel streams being determined by the rate of flow and the transverse position of the path of the combined fuel stream, an increase in the rate of flow of the control fuel stream causing a decrease in the rate of flow of the metered fuel stream.

4. The fuel metering system of claim 3 wherein said means for varying the rate of flow of the control fuel stream comprises a manually adjustable valvev 5. The fuel metering system of claim 3 wherein said fuel pump means delivers fuel from said supply at flow rates proportional to the speed of the engine, wherein said air inlet includes a throttle for controlling air flow therethrough, and wherein said means for varying the rate of flow of the control fuel stream comprises valve means responsive to the pressure in said air inlet downstream of said throttle, said valve means permitting an increase in the rate of flow of the control fuel stream upon a decrease in such pressure.

6. A fuel metering system for an internal combustion engine having a fuel supply, said fuel metering system comprising fuel pump means for delivering fuel from said supply at flow rates proportional to the speed of the engine; an air inlet for combustion air flow to the engine; a throttle disposed in said air inlet for controlling air flow therethrough; a fluid amplifier arrangement having an inlet chamber connected to said fuel pump means for receiving fuel at fuel flow rates proportional to the speed of the engine, an interaction region including upstream and downstream ends, a passage extending from said inlet chamber to an inlet port opening into said interaction region at said upstream end for discharging a main fuel stream longitudinally through said interaction region, a control.

passage extending from said inlet chamber to a control port opening into said interaction region at one side thereof for discharging a control fuel stream transversely through said interaction region into contact with the main fuel stream discharged from said inlet port, valve means in said control path having a transverse position varying in accordance with the rate of flow of the control fuel stream, a divider disposed in the path of the combined fuel stream, the combined fuel stream striking said divider to form a metered fuel stream and a surplus fuel stream, a metered fuel outlet opening from said downstream end of said interaction region and disposed on the side of said divider most closely adjacent said side of said interactio'n region into which said control port opens, said metered fuel outlet receiving the metered fuel stream from said interaction region and being connected to said air inlet for delivering the metered fuel stream to said air inlet for mixture with the combustion air flow, and a surplus fuel outlet opening from said downstream end of said interaction region and disposed on the side of said divider opposite said metered fuel outlet, said surplus fuel outlet receiving the surplus fuel stream from said interaction region and being adapted for connection to said fuel supply for delivering the surplus fuel stream to said fuel supply.

7. The fuel metering system of claim 6 which also includes additional valve means in said control passage for further regulating the rate of flow of the control fuel stream in accordance with engine operating requirements.

g;;g UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,598,096 Dated August 10, v 1971 l fl Fred F. Timpner It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 26, "the" (second occurrence) should be to Column 2, line 46, "traverse" should be transverse Column 3, claim 1, line 16, "stream" should be upstream Signed and sealed this 7th day of March 1972.

(SEAL) Atte st:

EDWARD M.FLbJTCHbJR,JR. ROBERT GO'ITSCHALK Attesting Officer Commissioner of Patents 

1. A fuel metering system for an internal combustion engine having a fuel supply and fuel pump means for delivering fuel from said supply at flow rates proportional to the speed of the engine, said fuel metering system comprising: an air inlet for combustion air flow to the engine; a throttle disposed in said air inlet for controlling air flow therethrough; a fluid amplifier arrangement having an interaction region including upstream and downstream ends, an inlet port opening into said stream end of said interaction region, said inlet port being adapted for connection to said pump means for receiving fuel at fuel flow rates proportional to the speed of the engine and for discharging a main fuel stream longitudinally through said interaction region, a pair of outlet ports opening from said downstream end of said interaction region, a divider separating said outlet ports, one of said outlet ports receiving a metered fuel stream from said interaction region and being connected to said air inlet for delivering the metered fuel stream to said air inlet for mixture with the combustion air flow, the other of said outlet ports receiving a surplus fuel stream from said interaction region and being adapted for connection to said fuel supply for delivering the surplus fuel stream to said fuel supply, and a control port opening into said interaction region for discharging a control fuel stream transversely through said interaction region into contact with the main fuel stream discharge from said inlet port; and means for varying the rate of flow of the control fuel stream in accordance with changes in the pressure in said air inlet downstream of said throttle; the main and control fuel streams forming a combined fuel stream passing longitudinally through said interaction region along a path having a transverse position varying in accordance with the rate of flow of the control fuel stream, the combined fuel stream striking said divider and forming the metered and surplus fuel streams received by said outlet ports, the rates of flow of the metered and surplus fuel streams being determined by the rate of flow and the transverse position of the path of the combined fuel stream, an increase in engine speed causing an increase in the rate of flow of the metered fuel stream delivered to said air inlet, and an increase in the pressure in said air inlet downstream of said throttle causing an increase in the rate of flow of the metered fuel stream delivered to said air inlet.
 2. A fuel metering system for an internal combustion engine comprising: a fuel supply; fuel pump means for delivering fuel from said supply; an air inlet for combustion air flow to the engine; a fluid amplifier arrangement having an interaction region including upstream and downstream ends, an inlet port opening into said upstream end of said iNteraction region and connected to said fuel pump means for discharging a main fuel stream longitudinally through said interaction region, a pair of outlet ports opening from said downstream end of said interaction region, a divider separating said outlet ports, one of said outlet ports receiving a metered fuel stream from said interaction region and being connected to said air inlet for delivering the metered fuel stream to said air inlet for mixture with the combustion air flow, the other of said outlet ports receiving a surplus fuel stream from said interaction region and being connected to said fuel supply for delivering the surplus fuel stream to said fuel supply, and a control port opening into said interaction region and connected to said fuel pump means for discharging a control fuel stream transversely through said interaction region into contact with the main fuel stream discharged from said inlet port; and means for varying the rate of flow of the control fuel stream in accordance with engine operating conditions; the main and control fuel streams forming a combined fuel stream passing longitudinally through said interaction region along a path having a transverse position varying in accordance with the rate of flow of the control fuel stream, the combined fuel stream striking said divider and forming the metered and surplus fuel stream received by said outlet ports, the rates of flow of the metered and surplus fuel streams being determined by the rate of flow and the transverse position of the path of the combined fuel stream.
 3. A fuel metering system for an internal combustion engine comprising: a fuel supply; fuel pump means for delivering fuel from said supply; an air inlet for combustion air flow to the engine; a fluid amplifier arrangement having an interaction region including upstream and downstream ends, an inlet port opening into said upstream end of said interaction region and connected to said fuel pump means for discharging a main fuel stream longitudinally through said interaction region, a divider formed at said downstream end of said interaction region, a metered fuel outlet port opening from said downstream end of said interaction region adjacent one side of said divider for receiving a metered fuel stream from said interaction region, said metered fuel outlet port being connected to said air inlet for delivering the metered fuel stream to said air inlet for mixture with the combustion air flow, a surplus fuel outlet port opening from said downstream end of said interaction region adjacent the opposite side of said divider for receiving a surplus fuel stream from said interaction region, said surplus fuel outlet port being connected to said fuel supply for delivering the surplus fuel stream to said fuel supply, and a control port opening into said interaction region on the side thereof most closely adjacent said metered fuel outlet port and connected to said fuel pump means for discharging a control fuel stream transversely through said interaction region into contact with said main fuel stream; and means for varying the rate of flow of the control fuel stream in accordance with engine operating conditions; the main and control fuel streams forming a combined fuel stream passing longitudinally through said interaction region along a path having a transverse position varying in accordance with the rate of flow of the control fuel stream, the combined fuel stream striking said divider and forming the metered and surplus fuel streams received by said outlet ports, the rates of flow of the metered and surplus fuel streams being determined by the rate of flow and the transverse position of the path of the combined fuel stream, an increase in the rate of flow of the control fuel stream causing a decrease in the rate of flow of the metered fuel stream.
 4. The fuel metering system of claim 3 wherein said means for varying the rate of flow of the control fuel stream comprises a manually adjustable valve.
 5. The fuel metering system of claim 3 wherein said fuel pump means delivers fuel from said supply at flow rates proportional to the speed of the engine, wherein said air inlet includes a throttle for controlling air flow therethrough, and wherein said means for varying the rate of flow of the control fuel stream comprises valve means responsive to the pressure in said air inlet downstream of said throttle, said valve means permitting an increase in the rate of flow of the control fuel stream upon a decrease in such pressure.
 6. A fuel metering system for an internal combustion engine having a fuel supply, said fuel metering system comprising fuel pump means for delivering fuel from said supply at flow rates proportional to the speed of the engine; an air inlet for combustion air flow to the engine; a throttle disposed in said air inlet for controlling air flow therethrough; a fluid amplifier arrangement having an inlet chamber connected to said fuel pump means for receiving fuel at fuel flow rates proportional to the speed of the engine, an interaction region including upstream and downstream ends, a passage extending from said inlet chamber to an inlet port opening into said interaction region at said upstream end for discharging a main fuel stream longitudinally through said interaction region, a control passage extending from said inlet chamber to a control port opening into said interaction region at one side thereof for discharging a control fuel stream transversely through said interaction region into contact with the main fuel stream discharged from said inlet port, valve means in said control passage for regulating the rate of flow of the control fuel stream, means for positioning said valve means in accordance with the pressure in said air inlet downstream of said throttle and operative to permit an increase in the rate of flow of the control stream upon an increase in such pressure, said main and control fuel streams forming a combined fuel stream passing longitudinally through said interaction region along a path having a transverse position varying in accordance with the rate of flow of the control fuel stream, a divider disposed in the path of the combined fuel stream, the combined fuel stream striking said divider to form a metered fuel stream and a surplus fuel stream, a metered fuel outlet opening from said downstream end of said interaction region and disposed on the side of said divider most closely adjacent said side of said interaction region into which said control port opens, said metered fuel outlet receiving the metered fuel stream from said interaction region and being connected to said air inlet for delivering the metered fuel stream to said air inlet for mixture with the combustion air flow, and a surplus fuel outlet opening from said downstream end of said interaction region and disposed on the side of said divider opposite said metered fuel outlet, said surplus fuel outlet receiving the surplus fuel stream from said interaction region and being adapted for connection to said fuel supply for delivering the surplus fuel stream to said fuel supply.
 7. The fuel metering system of claim 6 which also includes additional valve means in said control passage for further regulating the rate of flow of the control fuel stream in accordance with engine operating requirements. 